Allow rails 3 controllers to return streaming records. Support returning a valid JSON array, or raw file attachment in user specified format.

In your controller:

include Streamer

respond_to do |format|
  format.text do
    stream_to('users.txt') do |output|
      User.find_each do |u|
        output.write "#{u.name} #{u.email}\n"
      end
    end
  end

  format.json do
    stream_json do |output|
      User.find_each do |u|

# will be rendered as an object in a json array container

        send_record(u)
      end
    end
  end
end

Inspiration from patshaughnessy’s blog. This is useful for returning large record sets without an initial server delay.

Copyright © 2011 Drew Robb. released under the MIT license